DR region specific antibody ameliorated but ouabain worsened renal injury in nephrectomized rats through regulating Na,K-ATPase mediated signaling pathways

Reduced Na(+)-K(+)-ATPase function is reported in various renal diseases. This implies that increase of Na(+)-K(+)-ATPase function may be a new target in treatment of renal injury. We previously reported that Na(+)-K(+)-ATPase was stabilized by DRm217, a specific antibody against DR region of Na(+)-K(+)-ATPase. In this study, we compared the protective effect of DRm217 and ouabain on kidney in a chronic kidney disease rat model and investigated the mechanism under it. We found that DRm217 improved renal function, alleviated glomerulus atrophy, inhibited renal tubular cells apoptosis, tubulointerstitial injury and renal fibrosis in 5/6 nephrectomized rats. Contrary to DRm217, ouabain worsened renal damage. Activated Na(+)-K(+)-ATPase /Src signaling pathway, increased oxidant stress and activated inflammasome were responsible for nephrectomized or ouabain-induced renal injury. DRm217 inhibited Na(+)-K(+)-ATPase /Src signaling pathway, retarded oxidant stress, suppressed inflammasome activation, and improved renal function, suggesting a novel approach to prevent renal damage.